Colored cellulosic composition



Patented June 12, 1934 r COLORED CELLULOSIC COMPOSITION Alphons 0.Jaeger, Mount Lebanon, Pa., assignor to The Selden Company, Pittsburgh,Pa., a corporation of Delaware No Drawing. Application January 21,1931,- Serial No. 510,281

1 Claim. (01. 106- 22) This invention relates to compositionscontainpermit the formation of coating compositions ing coloredcellulose esters of organic acids and With-relatively cheap solventswhich yet have the more particularly is directed to compositionsdesirable properties of compositions which concontaining coloredcellulose acetate. ta'n much more expensive high boiling solvents.

In the past cellulose acetate has been used to These preferred modifiers.or compatible mate some extent for molding plastics and particurialinclude the class of synthetic resinous malarly for coating compositionsor films. It preterials produced by the reaction of polyhydric sentsmany advantages over the cheaper nitroalcohols with polybasic acids orcertain monocellulose from the standpoint of non-inflammabasic acids andparticularly with both polybasic 0 bility, safety from the formation ofpoisonous and monobasic acids. Examples of these resinfumes on burning,etc. Nevertheless cellulose ous materials are those produced by thereaction acetate and other organic esters of cellulose such of glycerin,glycol, glycol'ethers, glycerin ethers,

as cellulose formate and the like have not etc. with phthalicanliydride, maleic acid, fu-

achieved the commercial success in the field of maric acid, succinicacid, malic acid, adip acid colored plastics and coating compositions toor tartaric acid, modified with a monobasic acid which their propertieswould entitle them. This or glyceride monobasic acid, for examplebenzoic has largely been due to the difficulty of prepar-- acid, rosin,other natural acid resins such as ing colored cellulose acetate orsimilar organic congo, copal or higher fatty acids such as, for esterswhich are fast to light and which compoexample, stearic acid, palmiticacid, lactic acid,

20 sitions form tough, easily workable products. oleic acid, the acidsof cocoanut oil, soya-bean 7 But few dyes are capable of dyeingcellulose aceoil and other oils, d y n S y tate compositions, and inmany cases these dyes drying. ot er ass s ed y t e re are relativelyfugitive. The most resistant colaction of polyhydric alcohols withbenzoic acid, ors, for example the best vat dyes, almost withbenzoyl-beno c ac a its 1101110109168, p out exception will not dye celluloseacetate. thoylbenzoic acid and other keto aromatic acids 8 It ispossible to introduce durable colors into With or without phtha-l c fl yd 0 S m la cellulose acetate by dyeing the cellulose before dibasicacid. Other. compatible fiexibilizing it is acetylated with a dye whichis not destroyed agents are mo ified ld hyde mine condensaby theacetylating reagents. A satisfactory 001- tion products such as, forexample, products ob- 30 or can thus be obtained, but the products aretained by the condensation of monoor dimethyl commercially worthlessbecause they do not posurea with Dh a a yd a d e like. Cersesssufficient flexibility and toughness for either tain polyhydric alcoholpolyor monobasic acid high-grade molding compositions or coatingcomresins may be P ep including ym y positions nd fi1ms AlthQugh this mthod f benzoic acid or its lactone phthalide or derivadyeing celluloseacetate was proposed as early tives thereof and are particularly useful.With as 1911, nothing has ever been done With it practhe exception ofthe resins containing phthalide tically because of the lack offlexibility and workor other derivatives of OXy e O c c d ability of theproducts bt ined, and certain resins containing higher keto aro-According to the re t in tion cellulose matic acids these compatibleresins are not new 40 a tate compositions or compositions Of similarproducts and are therefore claimed only in conorganic esters such ascellulose formate, euunection with the colored cellulose estercomposilose propionate, cellulose butyrate, cellulose tions of thepresent invention. stearate, cellulose palmitate, celluose benzoate Whena suitable compatible flexibilizing agent or celulose ,phthalate areprepared by coloring is used a coating composition can be prepared 45the cellulose with suitable dyes capable of resist- W t elat y Che p owb g Solvents which ing the esterification process and the colored d sreadily but Which (106$ not Crack, p cellulose ester is thenincorporated with com-' blush. A great saving, of course, is effected bypatible fiexibilizing agents which render the eliminating the expensivehigh-boiling solvents plastics and coating compositions flexible andwhich are necessary if a fiEXib agent is not 50 tough without in any wayaffecting the beautiused, and the products are far superior in toughfulfast colors of the colored ester. While any ness and flexibility tothose obtained from colcompatible flexibilizing agent can be used,proored cellulose acetate alone. vided it is not of a color or turbiditywhich will Another important group of flexibilizing agents deleteriouslyaffect the color of the final compoare the nonalkali forming metal saltsand esters 55 sition, I prefer to use modifying agents which of the ketoaromatic acids. These agents are not 113- claimed per se in the presentapplication except in combination with the colored cellulose esters, butform respectively the subject matter of the application of L. C. DanielsSerial No. 476,715 filed August 20, 1930 and A. O. Jaeger Serial No.395,966 filed September 28, 1929.

Where it is desiredto produce colored brush lacquers or where cheaptoxic diluents or extenders such as benzol are used, it is sometimesdesirable to incorporate an agent which prevents rapid setting or rapidevaporation of the poisonous extender at low temperatures. Certainwaxes, particularly hydrocarbon waxes and ceresine,

ozokerite and the like may be used in small quantities.

Other plasticizers such as esters of phthalic anhydride, toluenesulphonamides; esters of aliphatic dibasic acids may also be used andare included.

Some of the preferred polyhydric alcohol polyor monobasic acid resinsused in flexibilizing the colored cellulose esters may show a ratherhigh acid number which is frequently undesirable when the product is tobe used on or in connection with metals which are easily attacked byacids. In such cases basic material may be added to neutralize theexcess acid. Among such bases,

ammonia, amines such as aniline, imides such as urea, certain imidederivatives such as basic derivatives of phthalimide, etc. may be used.Care should be taken in the case of high acid number in usingneutralizing agents such as ammonia as the product may be rendered watersoluble or at least may not resist water to a satisfactory degree.

While beautiful colors may be obtained by introducing the coloredcellulose ester alone, it is sometimes desirable to use a relativelymajor .portion' of flexibilizing agent, and in such cases additionalcolor may have to be introduced. This, of course, can be done byincorporating pigments, but the color isthen opaque and the advantagesof the beautifully transparent, completely uniform color which isobtained by the colored cellulose ester itself are sacrificed; while inits broader aspects such compositions are included, it is preferredwhere more highly colored material is desired to incorporate the colorin the form of a solution. This presents some difllculty because thehighly resistant colors, especially vat dyes which are preferred indyeing the cellulbse ester, are not soluble in the ordinary solvents.However, they are soluble in phthalide which is itself a goodflexibilizing agent and they may accordingly be incorporated in solutionin phthalide.

The preferred compositions of the present invention may be used withsolvents which need not be completely dehydrated as there is no tendencyfor the coating compositions to blush even though no high boiling watereliminants are used, nor is the clear color of the cellulose ester inany way affected. As many of the ordinary solvents used are somewhatdifficult to dehydrate and this always adds to the cost of the product,the resistance to small moisture content of the solvents is an addedadvantage of the composition of the present invention, but of course inits broader aspects the invention includes compositions in which all ofthe compositions are absolutely anhydrous. In coating compositions madeaccording to the present invention the solvents may be the ordinarycheap low boiling solvents and extenders used in dissolving the ordinarycellulose acetate compositions, it being an advantage of the presentinvention that no new solvents are required. The present invention is,therefore, not particularly concerned with any special solvents orsolvent mixtures except that it permitsthe use of solvent mixtures whichdo not contain high-boiling solvent eliminants or blush preventativesolvents.

The invention will. be described in greater detail in connection withthe following specific examples which illustrate typical modificationsand applications of the invention.

Example 1 Cotton linters are dyed with 2% of dimethyl dinaphthylimide, abeautiful deep rose color being obtained on oxidizing the vat color inair. 200 parts of the dyed linters are then esterified with 1600 partsof a mixture of acetic anhydride and acetic acid to which 20 parts ofsulfuric acid has been added as a catalyst. A brilliant red solution isobtained which is precipitated with water, the cellulose ester iswashed, dried and dissolved in chloroform or acetone. This is mixed with300 parts of a resin prepared by reacting glycerin, phthalic anhydrideand the fatty acids of cocoanut oil in the proportion of 1 mol ofglycerin to 1 mol'phthalic anhydride and 1 mol of cocoanut oil fattyacid. The solution is thor- .oughly mixed and if desired suitableextenders colored film which shows great tough'nessand; v

flexibility and absolutely uniformfcoloii g 7 Instead of using dimethyldinaphthylimide, other perylene vat dyes may be used such as Cale donjade green, v iolanthrone, isoviolanthrone, indanthrene green B, etc.,beautiful colored lacquers being obtained.

Instead of using' the fatty acids the flexibilizing resin.

Example 2 Cellulose is dyed with indanthrene blue G. C. D.

of cocoanut I oil, cocoanut oil itself may be used in preparing 15' in a1-2 dyeing and is'acetylated or formylated 20 phthalic anhydride andphthalide, a resin obtained from glycol or monoethyl ether of glycol andphthalic anhydride may be used.

Example 3 Cellulose is dyed with a sulfur dye such as Katigen violet,about a 4% dyeing being used. The dyed cellulose is then acetylated orbutyrated as described in Example 1 and is incorporated with equalamounts of a resin obtained by the reaction of glycerin, phthalicanhydride .and

naphthoylbenzoic acid in equimolecular propor- 1 tions and zincbenzoylbenzoate. Sufficient solvent is added so that the materials canbe readily mixed on rolls and molded or formed into sheets, theresulting product showing a clear, brilliant violet and beingtransparent or translucent.

If desired, 2-5% of a plasticizer such as dibutyl phthalate, butylbenzoylbenzoate or phthalimidine may be added.

Example 4 Cotton is dyed with an algol color, such as algol red orred-orange and is acetylated as in Example 1. 100 parts of the dyedacetyl cellu lose is mixed with 100 parts of a resin prepared byreacting glycerin or glycol with 3 or 2 mols. of naphthoylbenzoic acidrespectively, together -with 10-20 parts of a resin obtained by thereaction of dimethanol urea with phthalic anhydride and 30 parts of aresin obtained by the reaction of equal parts of toluidine and tung oilwhich has been heated to about 285 C. in the presence of zinc chloride.The mixture does not give a transparent film but it does give abeautiful translucent film of brilliant color, the reddish tinge of thetoluidine-tung oil somewhat deepening the shade of the acetyl cellulose.

Exa mple 5 Acetyl cellulose is prepared as in Example 1, using dimethyldinaphthylimide or Caledon jade green as a dye. A plastic composition isthen formed with an equal amount of rosin-phthalicglyceride resin. Anamount of phthalide equal to 20% of the acetyl cellulose is heated untilit melts and the same vat dye used in dyeing the acetyl cellulose isdissolved in the phthalide until a substantially saturated solution isobtained. This solution of the dye is then incorporated with the otheringredients, if, necessary with a small amount of solvent, and the wholeis worked on rolls until a uniform, deeply colored plastic is formedwhich then may be molded into sheets,

rods, etc. in the usual manner.

The examples set forth typical compositions falling under the presentinvention, and it should be understood that they may be used for thepurposes for which similar compositions are ordinarily employed. Thus,for example, all types of plastics may be prepared from' them, coatingcompositions of various types such as brushing lacquers, sprayinglacquers, priming coats and the like may be formed, and very desirablecoating compositions can be prepared for floor coverings such aslinoleums, coated asphalt, saturated felts and the like. colors of thecoating compositions, however, require in the case of some floorcoverings the addition of opacifying pigments such as zinc oxide,lithopone, etc., and of course where the inven- The brillianttransparent tion is used in coating compositions in which

